Centrifugal press



Oct. 3, 1967 K. PAUSE 3,344,738.

' CENTRIFUGAL PRESS Filed Jan. 22, 1965 2 Sheets-Sheet 1 Oct. 3, 1967 K. PAUSE CENTRIFUGAL PRESS Filed Jan. 22, 1965 Imam/r01? M 7" 7414 &

United States. Patent 33,42 11 Claims. (Cl. 100-116) The present invention relates to a centrifugal press, and more particularly to an improvement of a centrifugal separator of the type used for the removal of water from the residue remaining after the extraction of crushed sugar cane.

In accordance with the prior art, this residue, the socalled bagasse is subjected to very high mechanical pressure between three successively operating pairs of pressure rollers. These roller presses, which are also used for the extraction of juice from the roughly crushed sugar cane, are very heavy and expensive machines, but have nevertheless the disadvantage, when applied to the pressing of bagasse, that the extremely high pressure bruises and squashes the fibres so that further use of the bagasse for other purposes, for example in the manufacture of paper, is detrimentally affected.

In order to avoid this disadvantage, and to make possible the use of lighter and more compact machines, it has been proposed to remove the water from the bagasse by a centrifuge. Although machines were used which developed a centrifugal force of more than 2,000 times the acceleration of gravity, it was not possible to remove as much water from the bagasse as by the roller presses, and the bagasse still contained a great amount of mois ture after the centrifugal treatment, preventing the use of the bagasse for heating, or other industrial purposes.

The reason for the lesser efliciency of centrifuge for this purpose is that centifuges cannot develop the high specific pressure achieved between pairs of cooperating rollers which is between 1,600 kg./cm. and 1,700 kg./cm

This pressure is developed along the lines extending in axial direction of the pressure rollers and forming the gap through which the bagasse passes.

The meshed and felted fibres of the bagasse form interstices in which free water is held under atmospheric pressure. In the mechanical roller press, this water is removed by displacing and rearranging the fibres until all interstices are filled by closely adjacent fibres. In this process, the felted fibres are partly torn and squashed. However, the cells of the fibres form capillaries holding water at very high surface tension. In order to remove the water from the cells of the fibres, each fibre must be deformed and compressed in transverse direction, which requires comparatively small mechanical forces, since the fibres ofier only small resistance to transverse pressure. Consequently, the water contained in the capillaries, can be pressed out at compartively small pressure, while very high line pressures along the cooperating rollers are required for pressing the fibres against each other.

The present invention recognizes that the conditions prevailing during the removal of water from a fibrous substance, such as bagasse, by a centrifuge are completely different from the manner of operation of a mechanical press. The centrifugal force is capable of removing the water located in the interstices between the fibres without pressing the fibres together since the water moves outwardly under the action of the centrifugal force.

on the other hand, the removal of water from the cells and capillaries of the fibres, requires centrifugal forces of such magnitude that they cannot be produced in practically feasible centrifuges. While water between the fibres has a substantial mass and is subject to a great centrifugal force, the mass of water within a cell, and the mass of the cell wall are minute, so that only small forces are produced by the cell wall onto the water contained therein. As a result, when bagasse or a similar substance is centrifuged, only the free water between the fibres is removed, but the water contained within the cells and capillaries of the fibres remains.

It is one object of the invention to overcome these disadvantages of known centrifuges, and to provide a centrifuge capable of removing water not only from the interstices of a fibrous substance, but also from the cells of the fibres of the substance.

Another object of the invention is to achieve complete removal of water from a fibrous substance, such as bagasse, by simultaneously applying mechanical pressure and centrifugal force to the substance. 7

Another object of the invention is to provide a small and compact machine for the removal of water from bagasse to an extent which favorably compares with the results of a heavier and larger mechanical press.

A related object of the invention is to provide a small and comparatively inexpensive machine for the removal of water from bagasse.

Another object of the invention is to remove water from the interstices between the fibres of a fibrous substance by centrifugal force, and to subject the residue to the pressure developed by masses under the action of the centrifugal force. 7

With these objects in View, the present invention relates to a centrifugal press in which rotary presser means are actuated by the centrifugal force to press a liquid out of the residue remaining after a water holding substance has been subjected to the action of the centrifugal force.

One embodiment of the invention comprises a rotary filter drum; and rotary presser means, preferably including a plurality of presser members, mounted within the filter drum for movement toward the inner surface of the filter drum under the action of the centrifugal force.

The centrifugal force causes water located in the interstices between the fibres to pass through the filter drum, and the water contained in the ceIls'and capillaries of the fibres forming the residue, is squeezed out by the pressure of the presser members, and then passes through the filter drum.

In the preferred embodiment of the invention, the rotary presser means is reciprocatedin axial direction and has on the outside sawtooth-shaped projections opposite .tates the presser members. An operating member is preferably hydraulically actuated to reciprocate in axial direction along the shaft, and the presser members are mounted for pivotal movement on the movable operating member and are urged by the centrifugal force to swing outwardly toward the inner surface of the filter drum where the residue accumulates.

In the centrifugal press of the invention, the free water between the fibres is thrown outwardly through the openings in the filter drum by the action of the centrifugal force, while the presser'members squeeze the fibres in transverse direction to discharge the water held in the capillaries, and the thus discharged water also passes through the openings of the filter drum.

The mechanical pressure which is exerted by the presser members can be substantially smaller than the mechanical pressure prevailing in a conventional roller press, since the centrifugal presser members do not have to deform 3 the fibres to fill the interstices which is necessary for obtaining the effect of a mechanical roller press.

The action of the presser members is particularly effective, if they are provided with central axially extendingridges matching corresponding recesses in the filter drum, and preferably the filter drum includes a plurality of circumferentially adjacent filter elements having adjacent' edges forming gaps opposite the ridges and projections of the pressure members to facilitate the passage of squeezed out liquid to the outside.

The inlet at the smaller end of the frusto-conical filter drum is formed by a solid ring which has a stepped inner surface serving to' retain the substance supplied to the filter drum in cooperation with the rotary circular plate on which the supplied substance travels outwardly under the action of the centrifugal force toward the stepped inner surface.

It is advantageous to provide ribs for reinforcing the comparatively thin filter portion of the filter drum.

The novel features which are considered as characteristic for the invention are set forth in particular in the 'appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings, in which:

FIG. 1 is a vertical axial section illustrating an embodiment of a centrifugal press according to the invention, illustrating one operational position;

FIGURE 1a is a vertical section illustrating the device of FIGURE 1 in another position; and

FIG. 2 is a fragmentary cross section taken on line A-B in FIG. 1.

Referring now to the drawings, a drive shaft 1, mounted in a conventional manner in bearings and driven by a motor, not shown, carries a fixed piston 2 which is located within a cylinder member 3 mounted for axial movement along shaft 1, but being connected to the same for rotation. Piston 2 forms two chambers in cylinder 3, and two conduits 4 and 5 are provided in shaft 1 for supplying an operating liquid to the chambers on opposite sides of piston 2 whereby the movable cylinder member 3 is reciprocated along the shaft. Suitable valve means, not shown, control the flow of liquid into and out of the conduits 4 and 5 to achieve the axial reciprocation of cylinder member 3 While shaft 1 rotates with piston 2 and cylinder member 3.

The upper end of cylinder member 3 is closed by a circular plate 6 carrying a cylindrical collar surrounding shaft 1 spaced therefrom and projecting into a cylindrical portion of a bell-shaped housing 11. Suflicient space is provided between drive shaft 1 and the cylindrical portion of housing 11 to permit movement of collar 10 during the reciprocation and rotation of cylinder member 3.

A plurality of bearing brackets 8 are provided along the circumference of the circular plate 6 depending downwardly therefrom, and supporting shaft portions 8 of corresponding pressure members 9 which are spaced from 'drive shaft 1 rotates. Presser members 9 will also perform a reciprocating movement when cylinder member 3 is reciprocated.

The outer surface of each presser member 9 has sawtooth-shaped projections 9a forming presser faces and shoulders extending in circumferential direction and transverse to the axis of shaft 1. The free end portions of presser members 9 are thicker than the upper ends which are pivotally supported on the bearing brackets 7.

Each presser member has a roof-shaped outer surface with an extremity 9b, as best seen in FIG. 2, and the sawtooth-shaped projections 9a have a corresponding shape.

A filter drum surrounds the presser members and the hydraulic operating means 2, 3 and includes a rigid ring-shaped inlet portion 13 of frusto-conical shape, and a tubular filter portion 15 of slender frusto-conical shape. A hopper 21 is provided on one side of housing 11 for supplying a substance, such as bagasse, into the inlet of the filter drum formed by the ring-shaped solid member 13. Member 13 has a stepped innersurface composed of circular surface portions 14 which surround the circular plate 6 and form circular gaps with the'same, the thickness of the gaps depending on the position of cylinder member 3. The smallest circular gap is'formed in the position shown in the right portion of FIG. 1, where the peripheral edge of circular plate 6 is located opposite the cylindrical surface portion 14 having the smallest diameter. In the position of cylinder member 3 shown in the left portion of FIG. 1, the gap is substantially greater.

The comparatively thin filter portion 15 has substan-- tially axially extending ribs 16 which abut against a rigid outer annular wall 12 of frusto-conical configuration whose diameter is greater at the upper end thereof.

Filter drum 15 and wall 16 are connected to drive shaft 1 by a hub 18, spokes 19 and an outer ring 20 so as to rotate with drive shaft 1 and presser means 9.

As best seen in FIG. 2, the filter. portion 15 is composed of circumferentially adjacent axially elongated filter elements, each of which has outwardly projecting edge portions forming gaps 17 between each other. In the cross section of FIG. 2, the bent concave shape of the filter elements is clearly shown, and it will be seen that the innner surface of the filter portion 15 has projections and recesses alternating in circumferential directions, the recesses opening into gaps 17.

The central ridges of the roof-shaped outer surfaces of presser members 9 are located directly opposite gaps 17, and the configuration of 'the outer surface of each presser member 9 matches the shape of the recess formed by the edge portions of two adjacent filter elements.

The substance from which water is to be separated, for example bagasse from which sugar has been removed, and which was permitted to shed liquid by dripping, and which may be rinsed with fresh water, is periodically or continuously supplied through the hopper 21 into the inlet opening formed by the ring-shaped member 13.

The substance drops on the rotating circular plate 6 of the hydraulic cylinder member 3 and travels due to the action of the centrifugal force toward the inner surface of ring-shaped member 13 while being accelerated to the peripheral speed of plate 6. The substance is thrown against the inner surface of ring-shaped member 13 where the fibrous solid parts of the substance form a felted ring, while the free water moves outwardly and downwardly along the surfaces 14 and the inner surface of filter portion 15 to be discharged through gaps 17 between the filter elements. Due to the fact that the edge portions of the'filter elements project outwardly, the liquid travels along the same toward gaps 17. Liquid discharged from filter portion 15 moves toward the inner surface of the circular wall 12 in the spaces between ridges 16 and is upward stroke of cylinder member 3 with plate 6 to the 7 position shown on the right of FIG. 1, the annular residue on the inner surface of the filter drum is prevented from being discharged at the upper end of ring-shaped member 13 by the stepped inner surface 14. In this position, the gap between the uppermost inner surface portion 14 and the peripheral edge of circular plate 6 is substantially closed.

During the downward stroke of member 3 with plate 6 and presser members 9, the circular edge of plate 6 and the sawtooth-shaped projections of presser members 9 transport the residue downward along the inner surface of filter portion until the residue is discharged at the lower outlet end of filter" portion 15. At the same time, the centrifugal force acting on the presser members urges the same to turn outwardly about the pivots 8 and to press against the residue on the inner surface of filter portion 15.

Since the reciprocation of the presser members 9 is continuously repeated during rotation of drive shaft 1, an endless and compressed ring or tube of bagasse residue is formed on the inner surfaces of the filter elements forming filter portion 15 against which the presser members 9 are urged by the centrifugal force.

Due to the pressure of the presser members, the fibres of the bagasse are transversely compressed, and the water held in the capillaries of the fibres is squeezed out, passing through the gaps 17 between the filter elements to the outside.

Due to the continuously repeated action of the presser members 9, the bagasse ring passing out of the lower open 7 end of filter drum 15 is free of water and is torn to pieces by the action of the centrifugal force to pass through the opening between the spokes 19 in downward and outward direction.

The ribs 16 of the filter drum are not secured to the circular wall 12, but abut the same under the action of the centrifugal force so as to form a friction coupling causing the filter drum to turn with wall 12 and drive shaft 1. It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of centrifuges differing from the types described above.

While the invention has been illustrated and described as embodied in a centrifugal press for removing a liquid from a substance by centrifugal action, and by pressure of centrifugally actuated members, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be secured by Letters Patent is:

1. A centrifuge comprising, in combation, a rotary filter drum having an axis of rotation and being composed of a plurality of circumferentially adjacent filter elements having lateral edge portions separated from each other by gaps extending substantially in axial direction, said lateral edge portions projecting outwardly so that each filter element has a curved cross section in a plane erpendicular to said axis, said filter elements being adapted to permit passage of a liquid to the outside under the action of the centrifugal force and to retain a residue on the inner surface thereof; and rotary presser means mounted within said filter drum for movement toward said inner surface under the action of the centrifugal force, and including a plurality of presser members pivotally mounted within said filter drum staggered in circumferential direction to said filter elements, each presser member having an outer surface located opposite portions of two adjacent filter elements and having a contour matching the same so that the residue is subjected to mechanical pressure between said pressure members and the inner surfaces of said filter elements whereby liquid 6 is pressed out of the residue and passes through said filter drum under the action of the centrifugal force.

2. A centrifuge comprising, in combination, a rotary filter drum having an axis of rotation and being composed of a plurality of circumferentially adjacent filter elements having lateral edge portions separated from each other by gaps extending substantially in axial direction, said lateral edge portions projecting outwardly so that each filter element has a curved cross section in a plane perpendicular to said axis, said filter elements being adapted to permit passage of a liquid to the outside under the action of the centrifugal force and to retain a residue on the inner surface thereof; and rotary presser means including a plurality of presser members pivotally mounted within said filter drum for movement under the action of the centrifugal force toward the inner surfaces of said filter elements, each presser member having a roof-shaped outer surface forming a central ridge aligned with a corresponding gap between two adjacent filter ele ments and having a contour matching the shape of two adjacent filter elements so that the residue is subjected to mechanical pressure between said pressure members and the inner surfaces of said filter elements whereby liquid is pressed out of the residue and passes through said filter drum under the action of the centrifugal force.

3. A centrifuge comprising, in combination, a rotary filter drum having an axis of rotation and being composed of a plurality of circumferentially adjacent filter elements having lateral edge portions separated from each other by gaps extending substantially in axial direction, said lateral edge portions projecting outwardly so that each filter element has a curved cross section in a plane perpendicular to said axis, said filter elements being adapted to permit passage of a liquid to the outside under the action of the centrifugal force and to retain a residue on the inner surface thereof; rotary presser means including a plurality of presser members mounted within said filter drum for movement under the action of the centrifugal force toward the inner surfaces of said filter elements, each presser member having a roof-shaped outer surface forming a central ridge aligned with a corresponding gap between two adjacent filter elements and having a contour matching the shape of two adjacent filter elements so that the residue is subjected to mechanical pressure between said pressure members and the inner surfaces of said filter elements whereby liquid is pressed out of the residue and passes through said filter drum under the action of the centrifugal force; and operating means pivotally supporting said presser members for movement in radial planes under the action of the centrifugal force and axially reciprocating said rotary presser means along said inner surface of said drum whereby said residue is transported along said inner surface.

4. A centrifuge comprising, in combination, a rotary filter drum having an axis of rotation and being composed of a plurality of circumferentially adjacent filter elements having lateral edge portions separated from each other by gaps extending substantially in axial direction, said lateral edge portions projecting outwardly so that each filter element has a curved cross section in a plane perpendicular to said axis, said filter elements being adapted to permit passage of a liquid to the outside'unde'r the action of the centrifugal force and to retain a residue on the inner surface thereof; rotary presser means including a plurality of presser members mounted within said filter drum for movement under the action of the centrifugal force toward the inner surfaces of said filter elements, each presser member having a roof-shaped outer surface forming a central ridge aligned with a corresponding gap between two adjacent filter elements and having a contour matching the shape of two adjacent filter elements so that the residue is subjected to mechanical pressure between said pressure members and the inner surfaces of said filter elements whereby liquid is pressed out of the residue and passes through said filter drum under the action of the centrifugal force, said presser members having sawtooth-shaped projections on the outer surface thereof confronting said inner surface; and operating means pivotally supporting said presser members for movement in radial planes under the action of the cen trifugal force and axially reciprocating said rotary presser means along said inner surface of said drum whereby said residue is transported by said projections along said inner surface.

: 5. A centrifugal press comprising, in combination, a drive shaftthaving an axis; operating means including a movable member mounted on said drive shaft for reciprocal'movement in axial direction and for rotation therewith, and including a circular plate surrounding said shaft and located in a plane transverse to said axis; a filter drum including a ring-shaped solid inlet portion having an inner surface surrounding said plate, and a tubular substantially frusto-conical filter portion having its smaller 7 end secured to said ring-shaped inlet portion and its wider 7 said filter drum for movement in radial planes toward and away from the inner surface of said tubular filter portion and being reciprocable with said movable member in axial direction along said filter portion; and a housing enveloping said filter drum and having annular means spaced from said drive shaft and forming an inlet in the proximity of said inlet portion for supplying a substance containing solid fibers and a liquid through said inlet portion onto said plate whereby the substance travels outwardly under the action of the centrifugal force toward the inner surface of said ring-shaped inlet portion and from there onto the outer surface of sard presser members and the inner surface of sard tubular filter portion while said presser members are held by the centrifugal force on the inner surface of said filter portion whereby liquid is pressed out of the cells of the solid fibers of said substance and passes outwardly through said filter portion under the action of the centrifugal force in addition to liquid located between the fibers of the substance.

, 6. A centrifugal press comprising, in combination, a drive shaft having an axis; hydraulic operating means including a piston fixed on said drive shaft and a movable cylinder member mounted on said drive shaft for reciprocal movement in axial direction and for rotation therewith, and including a circular plate surrounding said shaft and located in a plane perpendicular to said axis;

a filter drum including a ring-shaped solid inlet portion having an inner surface surrounding said plate, and a tubular substantially frusto-conical filter portion having its smaller end secured to said ring-shaped inlet portion and its wider end open and forming an outlet, said filter drum being secured to said drive shaft for rotation therewith, and said filter portion having openings for the passage of a liquid to the outside under the action of the centrifugal force and retaining a residue on the inner surface thereof; a plurality of presser members pivotally mounted on said movable cylinder member of said operating means within said filter drum for movement in radial planes toward and away from the inner surface of said tubular filter portion and being reciprocable with said movable member in axial direction along said filter portion; and a housing enveloping said filter drum and having annular means spaced'from said drive shaft and forming an inlet in the proximity of said inlet portion for supplying a substance containing solid fibers and a liquid through said inlet portion onto said plate whereby the substance travels outwardly under the action of the centrifugal force toward the inner surface of said ringshaped inlet portion and from there onto the outer surface of said presser members and the inner surface of said tubular filter portion while said presser members are held by the centrifugal force on the inner surface of said filter portion whereby liquid is pressed out of the cells of the solid fibers of said substance and passes outwardly through said filter portion under the action of the centrifugal force in addition to liquid located between the fibers of the substance.

7. A centrifugal press comprising, in combination, a drive shaft having an axis; operating means including a movable member mounted on said drive shaft for reciprocal movement in axial direction and for rotation therewith, and including a circular plate surrounding said shaft and located in a plane perpendicular to said axis; a filter drum including a ring-shaped solid inlet portion having an inner surface surrounding said plate, and a t surface thereof; a plurality of presser members pivotallymounted on said movable member of said operating means within said filter drum for movement in radial planes toward and away from the inner surface of said tubular filter portion and being reciprocable with said movable.

member in axial direction along said filter portion, each of said presser members having sawtooth shaped projections on the outside thereof for moving the substance toward said outlet end of said filter portion during reciprocating movement of said presser members; and a housing enveloping said filter drum and having annular means spaced from said drive shaft and forming an inletin the proximity of said inlet portion for supplying a substance containing solid fibers and a liquid through said inlet portion onto said plate whereby the substance travels outwardly under the action of'the centrifugal force toward the inner surface of said ring-shaped inlet portion and from there onto the outer surface of said presser members and the inner surface of said tubular filter portion while said presser members are held by the centrifugal force on the inner surface of said filter portion whereby liquid is pressed out of the cells of the solid fibers of said substance and passes outwardly through said filter portion under the action of the centrifugal force in addition to liquid located between the fibers of the substance.

8. A centrifugal press comprising, in combination, a drive shaft having an axis; operating means including a movable member mounted on said drive shaft for reciprocal movement in axial direction and for rotation therewith, and including acir cular plate surrounding said said drive shaft for rotation therewith, and said filter portion having openings for the passage of a liquid to the 7 outside under the action of the centrifugal force and rethe outside thereof for moving the substance toward said outlet end of said filter portion during reciprocating movement of said presser members, each of said presser members having a roof-shaped ridge on the outside thereof located opposite one of said recesses in the inner surface of said filter portion and matching the shape of the same; and a housing enveloping said filter drum and having annular means spaced from said drive shaft and forming an inlet in the proximity of said inlet portion for supplying a substance containing solid fibers and a liquid through said inlet portion onto said plate whereby the substance travels outwardly under the action of the centrifugal force toward the inner surface of said ring-shaped inlet portion and from there onto the outer surface of said presser members and the inner surface of said tubular filter portion while said presser members are held by the centrifugal force on the inner surface of said filter portion whereby liquid is pressed out of the cells of the solid fibers of said substance and passes outwardly through said filter portion under the action of the centrifugal force in addition to liquid located between the fibers of the substance.

9. A centrifugal press as set forth in claim 8 wherein the inner surface of said inlet portion has stepped surface portions of different diameter forming circular gaps of different thicknesses with the periphery of said circular plate in different axially displaced positions of said plate and said movable member.

10. A centrifuge comprising, in combination, a rotary filter drum having a ring-shaped solid inlet portion having an inner surface composed of a plurality of stepped ringshaped surface portions of different diameter, and a tubular filter portion having one end secured to said inlet portion and the other end open and forming an outlet, said tubular filter portion having openings for the passage of a liquid to the outside under the action of the centrifugal force and retaining a residue on the inner surface thereof, said filter drum having axially extending reinforcing n'bs along the outer surface of said filter portion, and including a rigid annular wall surrounding said filter portion and said ribs and supporting the latter against outward movement; and rotary presser means mounted within said filter drum for movement toward said inner surface under the action of the centrifugal force so that the residue is subjected to mechanical pressure between said pressure means and said inner surface whereby liquid is pressed out of the residue and passes through said filter drum under the action of the centrifugal force.

11. A centrifugal press comprising, in combination, a drive shaft having an axis; operating means including a movable member mounted on said drive shaft for reciprocal movement in axial direction and for rotation therewith, and including a circular plate surrounding said shaft and located in a plane perpendicular to said axis; a filter drum including a ring-shaped solid inlet portion having an inner surface surrounding said plate, and a tubular substantially frusto-conical filter portion having its smaller end secured to said ring-shaped inlet portion and its wider end open and forming an outlet, said filter portion having an inner surface with recesses and projections alternating in circumferential direction and extending in axial direction, said filter drum having axially extending reinforcing ribs along the outer surface of said filter portion, and including a rigid annular wall surrounding said filter portion and said ribs and supporting the latter against outward movement, and a means securing said annular wall to said drive shaft for rotation therewith, and said filter portion having openings for the passage of a liquid to the outside under the action of the centrifugal force and retaining a residue on the inner surface thereof; a plurality of presser members pivotally mounted on said movable member of said operating means for movement in radial planes toward and away from the inner surface of said tubular filter portion and being reciprocable with said movable member in axial direction along said filter portion, each of said presser members having sawtooth shaped projections on the outside thereof for moving the substance toward said outlet end of said filter portion during reciprocating movement of said presser members, each of said presser members having a roof-shaped ridge on the outside thereof located opposite one of said recesses in the inner surface of said filter portion and matching the shape of the same; and a housing enveloping said filter drum and having annular means spaced from said drive shaft and forming an inlet in the proximity of said inlet portion for supplying a substance containing solid fibers and a liquid through said inlet portion onto said plate whereby the substance travels outwardly under the action of the centrifugal force toward the inner surface of said ring-shaped inlet portion and from there onto the outer surface of said presser members and the inner surface of said tubular filter portion while said presser members are held by the centrifugal force on the inner surface of said filter portion whereby liquid is pressed out of the cells of the solid fibers of said substance and passes outwardly through said filter portion under the action of the centrifugal force in addition to liquid located between the fibers of the substance.

References Cited UNITED STATES PATENTS 1,689,490 10/1928 Kelsey 210-376 2,808,935 10/1957 Sisley -116 X 3,136,722 6/1964 Gooch 210-376 OTHER REFERENCES German printed application 1,089,686 (Jarausch et al.), September 1960.

M. CARY NELSON, Primary Examiner.

H. T. KLINKSIEK, Assistant Examiner. 

1. A CENTRIFUGE COMPRISING, IN COMBINATION, A ROTARY FILTER DRUM HAVING AN AXIS OF ROTATION AND BEING COMPOSED OF A PLURALITY OF CIRCUMFERENTIALLY ADJACENT FILTER ELEMENTS HAVING LATERAL EDGE PORTIONS SEPARATED FROM EACH OTHER BY GAPS EXTENDING SUBSTANTIALLY IN AXIAL DIRECTION, SAID LATERAL EDGE PORTIONS PROJECTING OUTWARDLY SO THAT EACH FILTER ELEMENT HAS A CURVED CROSS SECTION IN A PLANE PERPENDICULAR TO SAID AXIS, SAID FILTER ELEMENTS BEING ADAPTED TO PERMIT PASSAGE OF A LIQUID TO THE OUTSIDE UNDER THE ACTION OF THE CENTRIFUGAL FORCE AND TO RETAIN A RESIDUE ON THE INNER SURFACE THEREOF; AND ROTARY PRESSER MEANSS MOUNTED WITHIN SAID FILTER DRUM FOR MOVEMENT TOWARD SAID INNER SURFACE UNDER THE ACTION OF THE CENTRIFUGAL FORCE, AND INCLUDING A PLURALITY OF PRESSER MEMBERS PIVOTALLY MOUNTED WITHIN SAID FILTER DRUM STAGGERED IN CIRCUMFERENTIAL DIRECTION TO SAID FILTER ELEMENTS, EACH PRESSER MEMBER HAVING AN OUTER SURFACE LOCATED OPPOSITE PORTIONS OF TWO ADJACENT FILTER ELEMENTS AND HAVING A CONTOUR MATCHING THE SAME SO THAT THE RESIDUE IS SUBJECTED TO 